CBS boss Nina Tassler said at the Television Critics Association’s winter TV previews that Colbert’s team has only just begun to work things out.

“They’ve actually just moved into their offices,” she said. “They’ve just started working. He will have music on the show. He said, ‘I have to be entertaining as my guests,’ so he’s going to have guests on the show. Whether or not he’s going to start with a monologue, he’s working on that right now. Clearly he knows that he’s introducing himself, the real Stephen Colbert to his audience. He’s really putting a lot of attention on making sure that the show is still topical and still relevant.”

“I have nine months to make a show, just like a baby,” Colbert said. “So first, I should find out how you make a baby.”

David Letterman, after 22 years at the helm of his show, will broadcast his last from the historic Ed Sullivan Theater on Wednesday, May 20.

CBS will air encores of its original programming throughout the summer in the 11:35 p.m. time slot, and may be interested in some Letterman specials leading up to his retirement.

The Colbert Report finale aired Dec. 18 on Comedy Central.

Newcomer to the USA TV market, British writer, actor and comedian James Corden is also on deck. Tassler said, “James Corden launches on Monday, March 23rd, and we’re announcing today that ‘The Late Show with Stephen Colbert’ will premiere on Tuesday, September 8th. We could not be more excited about these two new hosts and their incredible range of talent. Watching both of them getting ready for their new seasons had been an extraordinary opportunity. They are both more passionate and excited. With an election year ahead, it’s going to be nice to have the smartest guy in the room on at 11:30, and James Corden is putting together a staff and a group of writers that is truly one of the best in late night.”

As for Colbert, the process of moving out of his Colbert Report character will take some time. Tassler said, “…Stephen has said there’s a quote that is out there now, that it’s going to take nine months to make the show. It takes nine months to make a baby, so he said maybe we should learn how to make a baby, which is what he’s doing. This is really an additive process. He’s got almost all of his creative team from ‘The Colbert Report’ coming to work with him. He will have music on the show. He said repeatedly, ‘I have to be as entertaining as my guests,’ so we certainly will have guests on the show. Whether or not he’s going to start with an opening monologue, he’s working on that right now. But clearly he knows that he is introducing himself, the real Stephen Colbert, to his audience, and he’s really putting a lot of attention on making sure that the show is still topical, is still relevant, still dealing with current events. That’s really all he’s said so far.”

Corden, who is replacing Craig Ferguson, created and starred in the award-winning sitcom (2007-201o) Gavin & Stacey in Britain, is lesser known by American audiences but has the network’s full confidence. “James came into the room, and to say we were mesmerized by him was an understatement,” she said. “What he demonstrated in that room when Leslie [Moonves] and I met with him, you couldn’t take your eyes off of him. He’s so vibrant, he’s so entertaining. He’s a fearless actor. He’s pretty magic. It doesn’t matter who he talks to, they just fall under his spell. He’s enchanting.” Corden will debut as host on Monday, March 9.